How do I get an array slice of an ArrayList in Java? Specifically I want to do something like this: ArrayList<Integer> inputA = input.subList(0, input.size()/2); // where 'input' is a prepouplated ArrayList<Integer> So I expected this to work, but Java returns a List - so it's incompatible. And when I try to cast it, Java won't let m...
Hi, I have a problem with the following code. I obtain the error message Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 at java.util.ArrayList.rangeCheck(ArrayList.java:571) at java.util.ArrayList.set(ArrayList.java:364) at Test.main(Test.java:17) and I don't understand why. I have a lis...
Hi, I'm currently working with CodeGear Delphi 2007 under Vista. My application returns out of memory error during some rather heavy calculations. The .exe files grows from 150 Mb to an amazing 2 Gb (! LOL ) Regarding this issue: 1) I'm changing some arrays into arraylist BUT It's giving me some rather difficult issues to re...
I need to sort a shopping list by the aisle the item is located for example: [Bread] [1] [Milk] [2] [Cereal] [3] I am planning to do this with ArrayList and was wondering how to make an 2D ArrayList Bonus questions: any ideas on how to sort by the aisle number? ...
I currently believe that: When you need a structure from which you will be retrieving items randomly - use a HashMap When you will be retrieving items in order (e.g. using a for loop) - use an ArrayList Am I generally correct? Are there situations where this is not correct? ...
I am using the toString method of ArrayList to store ArrayList data into a String. My question is, how do I go the other way? Is there an existing method that will parse the data in the String back into an ArrayList? ...
I am wondering what is the memory overhead of java HashMap compared to ArrayList? Update: I would like to improve the speed for searching for specific values of a big pack (6 Millions+) of identical objects. Thus, I am thinking about using one or several HashMap instead of using ArrayList. But I am wondering what is the overhead of Ha...
Hi I am trying to copy the contents of an arraylist into another object. I tried initializing the new ArrayList object in the following ways newArrList.addAll(oldArrList); and newArrList = new ArrayList(oldArrList); But every time I make a change to one of the array lists, the value also changes in the other ArrayList. Can someon...
Hi all, If i have an ArrayList of type Integer, containing numbers like 1,3,4,9,10 etc... How can i display those on a JLabel, not the sum, but all the numbers in a sequence. So the JLabel would display, in this case: 134910 Thank you in advance for any help. EDIT: Thank you all, ofcourse i should have thought about append. Anyways, ...
Hi i have problem with a class i want to pass in an intent by putting it into the putExtras() Its serializable and the code looks like this: public abstract class ObjectA extends ArrayList<ObjectA> implements java.io.Serializable{...} public class ObjectB extends ObjectA {...} ... Bundle extras = new Bundle(); extras.putSerializable(...
I have a doubt that what is an array and what is an ArrayList? What is the different between them? ...
Hello! I am trying to make a method that takes the first Map whose values are sets and a second empty Map whose values are Lists and fills the second Map with the same key/value Mappings as the first. The 2nd map will have every key in the 1st Map, but associated with it is a List of all the same elements that are in the Set it maps to. ...
Is is possible to create a multidimensional list in C#. I can create an multidimensional array like so: string[,] results = new string[20, 2]; but I would like to be able to use some of the features in a list or arraylist like being able to add and delete elements. ...
Hello, Background: 3-4 weeks experience in Silverlight3/C#/.Net and about 3days worth with the RIA Services concept. (most of my previous questions up to date should explain why) I am doing a test implementation of Microsoft's RIA services with Silverlight3. This is part of a proof of concept i have to do for a client. So its very basi...
Consider the following two snippets of code: int index = 676; List<String> strings = new ArrayList<String>(); strings.add(index, "foo"); and int index = 676; List<String> strings = new ArrayList<String>(); strings.ensureCapacity(index); strings.add(index, "foo"); In the first case, I'm not surprised to see an IndexOfOutBoundsExcept...
I am using C# with a Windows Application Form. In this I have a combobox. What is the code to add the dropdown selections? From my googling so far I presume I need to setup an arraylist for the details? ...
Hi everyone, How can I randomised the order of pairs? e.g. I have 3 elements stored in list e.g. A,B,C --> which makes pairs of A-B, A-C, B-C. How can I display the pair in Random order? e.g. A-B, A-C, B-C or B-C, A-B, A-C or A-C, A-B,B-C ArrayList<String> s = new ArrayList<String>(); s.add("A"); s.add("B"); s.add("C"); ListGen...
Hi, I'm getting a Null ArrayList in a program i'm developing. For testing purposes I created this really small example that still has the same problem. I already tried diferent Primary Keys, but the problem persists. Any ideas or suggestions? 1-Employee class @PersistenceCapable(identityType = IdentityType.APPLICATION) public class Em...
Hi all, I decided to create a currency converter in Java, and have it so that it would pull the conversion values out of a text file (to allow for easy editability since these values are constantly changing). I did manage to do it by using the Scanner class and putting all the values into an ArrayList. Now I'm wondering if there is a w...
when i declared final arraylist() then can i perform insert,search and update operation in that arraylist or not??please reply me... thanks in advance ...